1. Field of the Invention
This invention relates to a sports shoe for preventing a heel portion thereof from rolling during running and also preventing a heel counter thereof from peeling off.
2. Description of Background Art
As for sports shoes such as running shoes or the like, shoe soles have generally been known, from a viewpoint of shock absorbing during running, wherein the shoe sole thereof is formed of a single layer of resilient foam material, as in the case of a sponge sole, or plural layers of resilient foam materials complying with various functions.
During the gait cycle of a runner wearing shoes of this type, his body weight load applied to the sole of the foot begins with the initial action of contacting a rearward outside portion of the heel portion with the ground. The load position is moved in sequence in conjunction with the subsequent contacting of the heel portion, the plantar arch portion and the ball portion of the fifth toe, and the final action of kicking off the ground with the first toe portion and the second-fifth toe portions. Accordingly, the shoe sole is compressed to be deformed in accordance with the above movement of the body weight loaded thereon, so that the heel portion of the shoe is rolled or laterally inclined during the period of time from the initial ground contacting, through the succeeding contacting, to the kick off action. It is possible that this rolling motion of the heel portion may be a cause of injury to the ankle or the knee joint.
To overcome the above defect, there has been hitherto proposed a sports shoe as disclosed in Japanese Patent Publication No. Sho 57-21321, Japanese unexamined utility model application Publication No. Sho 57-74708 and Japanese unexamined utility model application Publication No. Sho 57-76504. A hard counter is provided with a heel reinforcement wall which is shaped in conformity with an outer surface of a heel portion of an upper. An attaching portion includes an outer periphery portion which is provided with a heel reinforcement wall so as to be integral therewith. The heel reinforcement wall thereof is adhered to the outer surface of the heel portion of the upper and an attaching portion thereof is interposed between and adhered to an inwardly bent portion of the upper and a shoe sole so that the heel portion may be prevented from rolling by the hard counter.
However, since the attaching portion and the heel reinforcement wall of the hard counter of the proposed shoe meet one with another at right angles and since the shoe sole is made of a resilient foam material, the body weight load of a runner wearing the proposed shoe, during running, is applied largely to a boundary line between the attaching portion and the heel reinforcement wall. In this manner, the shoe sole of the resilient foam material is compressed excessively at a portion extending along the foregoing boundary line, and in conjunction therewith the hard counter is brought into a laterally inclined condition. As a result, the hard counter is defective not only in not sufficiently preventing rolling motion of the heel portion of the shoe during running, but also in that the attaching portion of the counter and the shoe sole are liable to be separated one from another along the foregoing boundary line.